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These three materials of stainless steel 304, 304H and 304L are often used in valve industry. Among three, 304 is the most common one, like SS304 ball valve, SS304 gate valve, SS304 globe valve, SS304 check valve we often see. In fact, according to the content of chromium and nickel, they all belong to stainless steel 304, since they all contains 18% chromium (Cr) and 8% nickel (Ni). The ma...
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For trunnion-mounted ball valve, there is a metal seat ring and a soft seat insert to ensure the sealing performance of seat. The seat inserts are element mounted inside a metal seat ring and perform the same sealing functions as seat ring. There are mainly two types of seat insert materials, elastomeric and thermoplastic. Elastomeric seat insert is softer to achieve zero leakage of ball valve. Wh...
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To understand the difference between globe valve and stop check valve, we should first figure out what is a stop check valve. Stop check valve combines the functions of a general globe valve and check valve, which means besides isolating and regulating the flow rate, it can also prevent reverse flow. From the appearance, globe valve and stop check valve almost look the same. The main difference li...
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People often have a confusion between a knife gate valve and slide gate valve. In brief, knife gate valve uses a blade to cut through thick liquids or gas; while a slide gate valve utilizes a slide plate to shut off flow of dry bulk material. In this article, we will discuss their differences in details. Knife Gate Valve Knife gate valves were originally designed for pulp and paper industry. ...
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1. What is the difference between Cast iron and Cast steel? The difference between Cast iron and Cast steel is their carbon content. Cast Iron with carbon content greater than 2.06% is iron; steel with carbon content between 0.02% and 2.06% is steel. 2. What is carbon steel? How many categories does it fall into? An alloy of carbon and iron (when the carbon content is between 0.02% and 2.06%) is c...
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In general, industrial valves don’t have to do a strength test in use. But repaired or corroded body and bonnet should do that. Common media used in valve pressure testing are water, oil, air, steam, nitrogen and so on. And valve pressure test methods of all kinds of industrial valves, including pneumatic, are as follows: 1.For ball valve The pneumatic test of the ball valve should be carried out ...
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